1. Field of the Invention
The present invention relates to a write-once optical recording medium, a method and apparatus for managing defect management information thereof, and more particularly, to a method and device for allocating a temporary defect management area, a method for allocating a spare area for defect management, and a write-once optical recording medium on which the temporary defect management area and the spare area are allocated on a type of the optical recording medium such as a write-once blu-ray disc.
2. Discussion of the Background Art
Optical discs, which are a kind of optical recording media, can record a large amount of data, and are now being widely used. Currently, a kind of innovative high-density digital versatile disc (HD-DVD) such as blue ray disc (Blu-ray Disc) is under development. This kind of medium can record and store video data of high quality and audio data of high fidelity for a long time.
The Blu-ray disc is a next generation optical recording solution that can store a larger amount of data than a conventional DVD.
The Blu-ray disc generally employs a blue-violet laser having a wavelength of 405 nm. This wavelength is shorter than a red laser used on a conventional DVD. The wavelength of the red laser is 650 nm. The Blu-ray disc has a thickness of 1.2 mm and a diameter of 12 cm, and includes a light transmission layer having a thickness of about 0.1 mm. Therefore, the Blu-ray disc can store a larger amount of data than a conventional DVD.
An optical disc device for writing and reading data on the Blu-ray disc is shown in FIG. 1. It includes an optical pick-up 11 for writing and reading a signal on/from an optical disc 10, a video disc recorder (VDR) system 12 for processing the signal read out from the optical pick-up 11 into a replay signal, or for modulating and processing an externally inputted data stream into a record signal suitable for recording, and an encoder 13 for encoding an externally inputted analog signal and outputting the encoded analog signal to the VDR system 12.
A Blu-ray disc can be of a rewritable type, which is referred to herein as a Blu-ray Disc Rewritable (BD-RE). A BD-RE has a rewritable capability, which enables video and audio data to be written, erased, and rewritten thereon repeatedly. The BD-RE (shown in FIG. 2) is divided into a lead-in area (LIA), a data area and a lead-out area (LOA), and the front and the rear of the data area are allocated to have an inner spare area (ISA) and an outer spare area (OSA).
With the BD-RE configured in the manner described above, the VDR system 12 of the optical disc device shown in FIG. 1 encodes and modulates externally inputted data into a signal suitable for recording, and records by cluster unit corresponding to error correction block unit. If a defective area occurs in the data area while recording data on the BD-RE, the data of one cluster unit recorded on the defective area is also recorded on the spare area (for example, the inner spare area on the BD-RE) according to a linear replacement operation. A series of linear replacement operations can be performed.
Accordingly, the VDR system 12 of the optical disc device records the data of the cluster unit recorded on the defective area onto the spare area, even if the defective area occurs in the data area of the rewritable Blu-ray disc. When a playback operation is performed for the rewritable Blu-ray disc, the data recorded onto the spare area are read out and replayed so that a data recording error can be prevented.
Various standards related to the Blu-ray disc are under development.
In this respect, a second type of Blu-ray disc, on which data is not repeatedly rewritten (non-rewritable), but is written only once, is herein referred to as a Blu-ray Disc Write-Once (BD-WO).
The Write-once Blu-Ray disc is useful when it is not desirable to repeatedly rewrite data. In a BD-WO, management of defective areas is needed.
Since data can be recorded on the BD-RE repeatedly (due to the characteristics of the BD-RE), the size of the defect management area (DMA) for the rewritable Blu-ray disc is relatively small (see DMA1-DMA4 in FIG. 2). In contrast, since data is recorded on the write-once Blu-ray disc only one time, the area required to manage the defective area for the BD-WO needs to be larger than the area required for the BD-RE. Accordingly, a sufficiently sized defect management area should be allocated for the BD-WO.
An effective defect management method for a BD-WO requires consistency and compatibility with standards that are applicable to the BD-RE, including consistency and compatibility related to recording and replaying of management information in order to obtain more efficient, more stable and higher performance in recording and replaying information and data. Thus, an innovative method, apparatus and structure for both recording and management of defective areas and related information for the BD-WO are needed.